My research examines childhood precursors of adolescent antisocial behavior (ASB) among separate samples of ADHD boys and girls. Unlike previous studies, key advantages here include: (a) rigorous diagnostic criteria for ADHD and comorbid conditions; (b) diverse predictors and outcomes; (c) sufficient ethnic and gender diversity; (d) a prospective design that enhances the specification of causal pathways. 177 boys (ages 6-12) participated in four separate naturalistic summer programs. Boys were observed during six-week camps with classroom and outdoor activities. About half of the boys had a diagnosis of ADHD and were actively treated with stimulants. The remaining boys served as normal comparisons. Observational data, including aggression and internalizing conditions were collected, as were peer sociometrics and academic achievement. Assessments were conducted prior to the camp and relevant measures were based on unmedicated periods. Five-years later, families were contacted for follow-up diagnostic interviews and questionnaires. Three samples have already been assessed and the final sample is currently being recruited. Similar summer programs were held for girls with and without ADHD (N=228); many fewer had medication histories. Four year follow-up visits will begin in Fall, 2001 and proceed annually until all three cohorts are assessed. The goal here is to (a) test childhood predictors of adolescent adjustment, with a focus on ASB and (b) test potential gender-specific predictions. Although possible cohort effects preclude precise comparisons, preliminary models will be constructed.